This invention relates to a bicycle crank and a method for manufacturing said crank.
More precisely, this invention relates to a bicycle crank comprising:
an elongated core with a first and a second end,
a first and a second insert arranged on the ends of said core, and
a high-resistance fibre coating incorporated in a plastic material matrix.
U.S. Pat. No. 6,202,506 describes a bicycle crank of the type specified above, wherein the inserts are foamed into a rigid plastic material forming the core of the crank. This document discloses a method for manufacturing a crank comprising the following steps: introducing into a mould one layer of fabric soaked in synthetic resin providing a partially open fibre-reinforced plastic casing, inserting a pair of inserts in the partially open casing, foaming the inserts with high-resistance foam, sealing the fibre-reinforced plastic material casing with at least one layer of fibre fabric soaked in plastic material, and hardening the fibre-reinforced plastic material and said foam.